Discharged sheet aligning device and image erasing apparatus including the same

ABSTRACT

According to one embodiment, a image erasing apparatus includes a paper feeding section configured to feed a sheet having a erasable image, a erasing section configured to erase the image, a paper discharge section including a paper discharge member configured to discharge, downstream in a conveying path of the erasing section, the sheet from which the image is erased and a paper discharge tray on which the discharged sheet is stacked, and a longitudinal alignment plate pivotably provided above the paper discharge tray and configured to align the leading end of the sheet stacked on the paper discharge tray.

CROSS-REFERENCE TO RELATED APPLICATION

This application is based upon and claims the benefit of priority from provisional U.S. Patent Application 61/493,376 filed on Jun. 3, 2011, the entire contents of which are incorporated herein by reference.

FIELD

Embodiments described herein relate generally to a discharged sheet aligning device that aligns discharged and stacked sheets and an image erasing apparatus including the discharged sheet aligning device.

BACKGROUND

In the past, a sheet processing apparatus such as a finisher includes a paper discharge tray on which discharged sheets are stacked. The paper discharge tray has a shape inclined downward on an upstream side in a sheet conveying direction. After being discharged onto the paper discharge tray, a discharged sheet returns to the upstream side and the trailing end of the sheet comes into contact with a wall surface of an apparatus main body.

However, in the paper discharge tray explained above, when a sheet on the paper discharge tray returns upstream, a sheet discharged next comes into contact with the sheet, the sheet may not be able to return to a fixed position, and alignability of the sheet is deteriorated.

On the other hand, there is a color erasing apparatus that erases a color of an image formed on a sheet to put the sheet into a reusable state. The color erasing apparatus includes a decoloring section that erases an image formed on a sheet and a stacking tray on which the sheet subjected to the erasing and made reusable is stacked.

After being picked up by a user, the sheet stacked on the stacking tray is set in a paper feeding cassette of an image forming apparatus. After picking up the sheet from the stacking tray, the user needs to adjust a sheet shift and then set the sheet in the image forming apparatus. Therefore, there is a demand for an apparatus that stacks a reusable sheet in a state with high alignability.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which is incorporated in and constitute a part of this specification, illustrates an embodiment of the invention and together with the description, serve to explain the principles of the invention.

FIG. 1 is an overall configuration diagram of a color erasing apparatus according to a first embodiment;

FIGS. 2A to 2C are schematic diagrams of a discharged sheet aligning device shown in FIG. 1;

FIGS. 3A to 3D are schematic diagrams of a discharged sheet aligning device according to a second embodiment;

FIGS. 4A to 4D are diagrams for explaining the operation of the discharged sheet aligning device according to the second embodiment;

FIGS. 5A to 5C are schematic diagrams of a discharged sheet aligning device according to a third embodiment;

FIGS. 6A to 6E are diagrams for explaining the operation of the discharged sheet aligning device according to the third embodiment; and

FIG. 7 is a schematic configuration diagram of a discharged sheet aligning device according to the embodiments applied to a finisher.

DETAILED DESCRIPTION

Reference will now be made in detail to the present embodiment of the invention, an example of which is illustrated in the accompanying drawing.

In general, according to one embodiment, a image erasing apparatus includes: a paper feeding section configured to feed a sheet having a erasable image; a erasing section configured to erase the image; a paper discharge section including a paper discharge member configured to discharge, downstream in a conveying path of the erasing section, the sheet from which the image is erased and a paper discharge tray on which the discharged sheet is stacked; and a longitudinal alignment plate pivotably provided above the paper discharge tray and configured to align the leading end of the sheet stacked on the paper discharge tray.

Embodiments are explained below with reference to the accompanying drawings. If the same reference numerals and signs are used in the following explanation, this means that components denoted by the reference numerals and signs have the same configurations and the functions.

First Embodiment

FIG. 1 is a schematic diagram of the overall configuration of a color erasing apparatus (decoloring apparatus or image erasing apparatus) according to a first embodiment. A color erasing apparatus 1 applies decoloring (erasing) processing for erasing a color of an image to a sheet P on which an image is formed by a decolorable color material (image erasable material) such as a decolorable toner or decolorable ink. The color erasing apparatus 1 includes a paper feeding section 101, a reading section 102, a decoloring section (erasing section) 103, a paper discharge section 104, a first conveying path 105, a second conveying path 106, a third conveying path 107, a first diverting member 108, a second diverting member 109, an operation section 110, and a control section 111.

The paper feeding section 101 includes a paper feeding tray 112 and a paper feeding member 113. Sheets P to be reused are stacked on the paper feeding tray 112. Sheets of various sizes such as A4, A3, and B5 are stacked on the paper feeding tray 112. The sheets P stacked on the paper feeding tray 112 are, for example, sheets subjected to image formation with a recording material that is decolored by being heated to temperature equal to or higher than predetermined temperature. The paper feeding member 113 includes a pickup roller, a sheet feeding roller, and a separating roller arranged to be opposed to the sheet feeding roller. The paper feeding member 113 feeds the sheets P on the paper feeding tray 112 to the first conveying path 105 on the inside of the color erasing apparatus 1 one by one. The paper feeding tray 112 includes a detection sensor 114 that detects presence or absence of a sheet on the paper feeding tray 112. The detection sensor 114 may be, for example, a micro sensor or a micro actuator.

The reading section 102 is arranged along the first conveying path 105 downstream in a sheet conveying direction with respect to the paper feeding tray 112. The reading section 102 includes a reading unit such as a CCD (Charge Coupled Device) scanner or a CMOS sensor. In this embodiment, the reading section 102 reads respective images on a first side and a second side of the conveyed sheet P. Specifically, the reading section 102 includes two reading units arranged along the first conveying path 105 and across the conveying path. The reading section 102 enables duplex reading of images on the conveyed sheet P. A position where the reading units of the reading section 102 read the images on the sheet P is referred to as reading position. The images read by the reading section 102 are stored in a memory described below in the control section 111. For example, images on the sheet P read by the reading section 102 before decoloring processing is performed are converted into an electronic form and stored in the memory. Consequently, if data of the decolored images is necessary later, the image data can be acquired. The control section 111 determines on the basis of the images read by the reading section 102 whether the sheet P is a decolorable sheet or a reusable sheet.

The first diverting member 108 functioning as switching section is present downstream of the reading section 102. The first diverting member 108 switches a conveying direction of the conveyed sheet P. The first diverting member 108 conveys the sheet P, which is conveyed through the first conveying path 105, to the paper discharge section 104 or the second conveying path 106. The second conveying path 106 branches from the first conveying path 105 at a branch point where the first diverting member 108 is arranged. The second conveying path 106 branching from the branch point conveys the sheet P to the decoloring section 103.

The decoloring section 103 erases a color of images on the conveyed sheet P (the decoloring section 103 decolors the image). For example, in a state in which the decoloring section 103 is in contact with the conveyed sheet P, the decoloring section 103 heats the sheet P to predetermined decoloring temperature to thereby erase a color of images formed on the sheet P with a recording material. For example, the decoloring section 103 of the erasing apparatus 1 according to this embodiment includes two decoloring units 103 a and 103 b for first side decoloring and second side decoloring for the sheet P. The decoloring units 103 a and 103 b are arranged to be opposed to each other across the second conveying path 106. The decoloring unit 103 a comes into contact with the sheet P from one side of the sheet P and heats the sheet P. The decoloring unit 103 b comes into contact with the sheet P from the other side and heats the sheet P. In other words, the decoloring section 103 decolors images on both sides of the conveyed sheet P in one conveyance. A position where the decoloring units 103 a and 103 b heat the sheet P, i.e., a position where heating sections (not shown in the figure) included in the decoloring units 103 a and 103 b apply heat to the conveyed sheet P and erases a color of the images is referred to as decoloring position. The decoloring section 103 includes temperature sensors 115 a and 115 b that respectively detect the temperatures of the heating sections of the decoloring units 103 a and 103 b. The temperature sensors 115 a and 115 b may be either a contact type or a noncontact type.

The paper discharge section 104 includes a paper discharge tray 116 and a paper discharge member 117. The paper discharge tray 116 includes a first paper discharge tray 116 a and a second paper discharge tray 116 b. The first paper discharge tray 116 a and the second paper discharge tray 116 b are vertically arranged. The first paper discharge tray 116 a includes a longitudinal alignment plate 118. The longitudinal alignment plate 118 is detachable. Elastic layers 116 c are provided on inner walls of the distal ends on a downstream side in the conveying direction of the first paper discharge tray 116 a and the second paper discharge tray 116 b. The distal ends on the downstream side in the conveying direction of the paper discharge trays are referred to as distal ends of the paper discharge trays as well. The first paper discharge tray 116 a and the second paper discharge tray 116 b respectively include stacking plates 119 a and 119 b and elastic members 120 a and 120 b. The stacking plates 119 a and 119 b are connected to the bottoms of the first paper discharge tray 116 a and the second paper discharge tray 116 b via the elastic members 120 a and 120 b. The stacking plates 119 a and 119 b are provided to incline downstream in the conveying direction. As more sheets are stacked on the stacking plates 119 a and 119 b, an upstream side in the conveying direction of the stacking plates 119 a and 119 b to which the elastic members 120 a and 120 b are connected gradually lowers.

The first paper discharge tray 116 a and the second paper discharge tray 116 b include aligning rollers 121 a and 121 b. The first paper discharge tray 116 a and the second paper discharge tray 116 b include stacking plate detection sensors 122 a and 122 b that detect the stacking plates 119 a and 119 b. For example, if the stacking plate detection sensor 122 a detects the stacking plate 119 a, the stacking plate detection sensor 122 a informs the control section 111 that the number of stacked sheets P₁ reaches an allowable number of stacked sheets of the paper discharge tray 116 a. The stacking plate detection sensors 122 a and 122 b may be, for example, micro sensors or micro actuators.

For example, the sheet P made reusable by decoloring of images formed thereon is stacked on the first paper discharge tray 116 a. The sheet P determined as unreusable is stacked on the second paper discharge tray 116 b. The paper discharge members 117 a and 117 b discharge the sheets P to the first paper discharge tray 116 a and the second paper discharge tray 116 b. The sheets P to be received by the first paper discharge tray 116 a and the second paper discharge tray 116 b can be interchanged. A user only has to set, for example, from the operation section 110, what kinds of sheets are stacked on the respective paper discharge trays, i.e., set conveying destinations of sheets. According to the setting, the second diverting member 109 switches a conveying path and guides the conveyed sheet P to the first paper discharge tray 116 a or the third conveying path 107.

The first conveying path 105 forms a conveying path extending from the paper feeding tray 112 to the first paper discharge tray 116 a. The first conveying path 105 conveys the fed sheet P to the reading section 102 or the first paper discharge tray 116 a. The first conveying path 105 includes the second diverting member 109 downstream of the first diverting member 108. The second diverting member 109 guides the sheet P, which is conveyed from the first diverting member 108, to the first paper discharge tray 116 a or the third conveying path 107. The third conveying path 107 conveys the sheet P to the second paper discharge tray 116 b.

The second conveying path 106 merges with the first conveying path 105 at a merging point 123 further upstream in the sheet conveying direction than the reading section 102. Specifically, the second conveying path 106 merges with the first conveying path 105 at the merging point 123 between the paper feeding section 101 and the reading section 102. Therefore, the second conveying path 106 makes it possible to convey the sheet P, which is conveyed from the reading section 102, to the reading section 102 again through the decoloring section 103. In other words, the color erasing apparatus 1 can control the first diverting member 108 to convey the sheet P, which is fed from the paper feeding member 113, to the reading section 102, the decoloring section 103, and the reading section 102 in this order.

The operation section 110 includes a display section of a touch panel type and various operation keys and is arranged in, for example, an upper part of a main body of the color erasing apparatus 1. The operation keys include, for example, a ten key, a stop key, and a start key. The user instructs, via the operation section 110, a functional operation of the color erasing apparatus 1 such as the start of decoloring or reading of images on the sheet P to be decolored. The display section of operation section 110 displays setting information, an operation status, and log information of the color erasing apparatus 1 or a message to the user. The operation section 110 is not limited to an operation section arranged in the main body of the color erasing apparatus 1. For example, the operation section 110 may be an operation section connected to an operation device of an external apparatus via a network to be capable of being operated from the operation device on the outside. In other words, the operation section 110 in this embodiment only has to be an operation section with which, for example, the user can instruct the color erasing apparatus 1 about processing and information browsing.

The control section 111 includes a processor including a CPU (Central Processing Unit) or an MPU (Micro Processing Unit) and a memory. The control section 111 controls the reading section 102, the decoloring section 103, and the operation section 110. The memory is, for example, a semiconductor memory and includes a ROM (Read Only Memory) having stored therein various control programs and a RAM (Random Access Memory) that provides the processor with a temporary work area. For example, the ROM has stored therein a printing ratio of a sheet set as a threshold for determining reusability and a density threshold for determining whether an image is decolored. The RAM may temporarily store an image read by the reading section 102.

A sheet conveying path is changed as appropriate on the basis of a processing mode executed by the color erasing apparatus 1. The color erasing apparatus 1 has plural processing modes. The color erasing apparatus 1 has, for example, (1) a first decoloring mode for performing only the decoloring processing without performing image reading, (2) a second decoloring mode for performing the decoloring processing after image reading, (3) a third decoloring mode for, after the decoloring processing, carrying out discrimination (discrimination processing) for determining reusability of the sheet P without performing reading processing before decoloring, (4) a fourth decoloring mode for carrying out the decoloring processing after image reading and further carrying out the discrimination processing, and (5) a reading mode for carrying out the image reading processing without performing image decoloring. The user can select these modes in the operation section 110 of the color erasing apparatus 1. The selection of the processing modes is not limited to the selection in the operation section 110 of the color erasing apparatus 1. The user may set the processing modes from an external terminal. In the first to fourth decoloring modes, the sheet P is always conveyed to the decoloring section 103. On the other hand, in the reading mode, the color erasing apparatus 1 controls the first diverting member 108 to discharge the sheet P through the reading section 102 without conveying the sheet P to the decoloring section 103.

The color erasing apparatus 1 includes plural sheet detection sensors 124, 125, 126, 127, and 128 that detect the sheet P conveyed through the first to third conveying paths 105, 106, and 107. The sheet detection sensors may be, for example, micro sensors or micro actuators. The sheet detection sensors are arranged in appropriate positions of the conveying paths.

A discharged sheet aligning device according to this embodiment is explained. FIGS. 2A to 2C are schematic diagrams of the first paper discharge tray 116 a and the longitudinal alignment plate 118. FIG. 2A is a top view of the first paper discharge tray 116 a and the longitudinal alignment plate 118. FIG. 2B is a sectional view of the first paper discharge tray 116 a and the longitudinal alignment plate 118 taken along line A-A′ in FIG. 2A. FIG. 2C is a front view of the first paper discharge tray 116 a and the longitudinal alignment plate 118 viewed from a Y direction in FIG. 2A.

As shown in FIGS. 2A to 2C, the longitudinal alignment plate 118 is a member including a bent section 118 a, one end of which is bent substantially vertically, and having a substantially L shape in cross section. The longitudinal alignment plate 118 includes an elastic layer 118 b on the inner wall of the bent section 118 a. On the paper discharge member 117 a side of the first paper discharge tray 116 a, i.e., on the upstream side in the conveying direction of the first paper discharge tray 116 a, the other end of the longitudinal alignment plate 118 is pivotably supported with the bent section 118 a faced to the first paper discharge tray 116 a side (a double-headed arrow Q in FIGS. 2B and 2C). The bent section 118 a comes into contact with a distal end 116 d on the downstream side in the conveying direction of the first paper discharge tray 116 a. In other words, the bent section 118 a of the longitudinal alignment plate 118 is freely opened and closed with respect to the distal end 116 d of the first paper discharge tray 116 a with the upstream side in the conveying direction set as an axis.

The paper discharge member 117 a discharges the sheet P₁ to the first paper discharge tray 116 a. The aligning roller 121 a further conveys the sheet P₁, which is discharged by the paper discharge member 117 a, to the distal end side of the paper discharge tray 116 a. The aligning roller 121 a is driven to bring the leading end of the sheet P₁ into contact with the elastic layer 116 c provided on the inner wall of the distal end of the paper discharge tray 116 a or the bent section 118 a of the longitudinal alignment plate 118. As the aligning roller 121 a, a roller made of a material having a low coefficient of friction such as sponge is used.

The upstream side in the conveying direction of the stacking plate 119 a, to which the elastic member 120 a is connected, gradually lower according to the number of stacked sheets P₁ subjected to the decoloring processing, i.e., the weight of the stacked sheets P₁. The elastic member 120 a expands and contracts according to urging from the stacking plate 119 a (a double-headed arrow R in FIG. 2B).

As explained above, in the first embodiment, the distal end of the longitudinal alignment plate 118 and the distal end of the paper discharge tray 116 a are in contact with each other during the paper discharge and the stacking of the sheet P1. Therefore, it is possible to prevent the discharged sheet P1 from sticking out from the paper discharge tray 116 a because of a warp or the like and perform longitudinal alignment of the stacked sheet P1.

Second Embodiment

A discharged sheet aligning device according to a second embodiment is explained. In a longitudinal alignment mechanism in the second embodiment, a longitudinal alignment plate, the length in a sheet conveying direction of which can be adjusted according to the size of a sheet to be subjected to erasing, is provided. In the second embodiment, detailed explanation is omitted concerning components same as the components explained in the first embodiment.

FIGS. 3A to 3D are schematic diagrams of the discharged sheet aligning device according to the second embodiment. FIG. 3A is a top view of the discharged sheet aligning device. FIG. 3B is a cross-sectional view of the discharged sheet aligning device taken along line B-B′ in FIG. 3A. FIG. 3C is a front view of the discharged sheet aligning device viewed from a Y direction in FIG. 3A. FIG. 3D is a diagram of the discharged sheet aligning device in which a sheet size is different from a sheet size shown in FIG. 3B.

As shown in FIGS. 3A to 3D, the discharged sheet aligning device according to the second embodiment includes a longitudinal alignment plate 200 and a paper discharge tray 203. The longitudinal alignment plate 200 and the paper discharge tray 203 are respectively equivalent to the longitudinal alignment plate 118 and the first paper discharge tray 116 a in the first embodiment. The longitudinal alignment plate 200 includes a first alignment plate 201 and a second alignment plate 202. The first alignment plate 201 and the second alignment plate 202 are separable. The first alignment plate 201 includes claws 201 b as first engaging sections. The first alignment plate 201 includes, at the distal end thereof, a bent section 201 a bent substantially vertically. The bent section 201 a includes an elastic layer 201 c. The bent section 201 a is formed in a shape that meshes with a distal end 203 a of the paper discharge tray 203 in a comb teeth shape (FIG. 3C). The paper discharge tray 203 includes an elastic layer 203 b on the inner wall of the distal end 203 a thereof. The second alignment plate 202 includes a pivot supporting section 202 a for pivotably attaching the second alignment plate 202 to the paper discharge member 117 a (see FIG. 1 and FIGS. 2A to 2C) or around the paper discharge member 117 a. The second alignment plate 202 includes a hollow in which the first alignment plate 201 is stored. The second alignment plate 202 includes, on the upper surface thereof, plural engaging holes, in which claws 201 b fit, as second engaging sections that engage with the first engaging sections. The engaging holes are provided at a predetermined interval along the conveying direction. The second alignment plate 202 includes a pressing member on the inner wall of a surface opposed to a surface including the engaging holes. The pressing member includes a pressing plate 202 b and an elastic body 202 c. The pressing member presses the first alignment plate 201, which is inserted into the second alignment plate 202, toward the upper surface. The first alignment plate 201 is inserted into the second alignment plate 202 or drawn out from the second alignment plate 202 according to the size of a sheet to be discharged such as A4, B5, or A3. In this embodiment, the first engaging sections are the claws 201 b and the second engaging sections are the engaging holes. However, the first engaging sections and the second engaging sections may be opposite.

FIGS. 4A to 4D are diagrams for explaining the operation of the longitudinal alignment plate 200 shown in FIGS. 3A to 3D. To adjust the longitudinal alignment plate 200 to the size of a sheet to be aligned, first, the first alignment plate 201 is inserted into the second alignment plate 202 (FIG. 4A). In the first alignment plate 201, the claws 201 b engage with the engaging holes of the second alignment plate 202 (FIG. 4B). If the size of a sheet to be discharged is large, i.e., if the first alignment plate 201 is drawn out from the second alignment plate 202, first, the first alignment plate 201 is pushed in a T direction, whereby the claws 201 b of the first alignment plate 201 are disengaged from the engaging holes of the second alignment plate 202 (FIG. 4C). Subsequently, the first alignment plate 201 disengaged from the engaging holes is drawn out from the second alignment plate 202 (FIG. 4D).

As explained above, in the second embodiment, in addition to the characteristics in the first embodiment, it is possible to perform longitudinal alignment corresponding to the size of a sheet to be discharged.

Third Embodiment

A discharged sheet aligning device according to a third embodiment is explained. In the discharged sheet aligning device according to the third embodiment, a guide that performs lateral alignment is provided in a longitudinal alignment plate. In the third embodiment, detailed explanation is omitted concerning components same as the components explained in the first and second embodiments.

FIGS. 5A to 5C are schematic diagrams of the discharged sheet aligning device according to the third embodiment. FIG. 5A is a top view of the discharged sheet aligning device. FIG. 5B is a cross-sectional view of the discharged sheet aligning device taken along line C-C′ in FIG. 5A. FIG. 5C is a diagram of a state in which a longitudinal alignment plate shown in FIG. 5B is opened.

As shown in FIGS. 5A to 5C, the discharged sheet aligning device according to the third embodiment includes a longitudinal alignment plate 300 and a paper discharge tray 301. Like the longitudinal alignment plates in the first and second embodiments, the longitudinal alignment plate 300 includes a bent section 300 a, the downstream distal end of which in a conveying direction is bent substantially vertically, and guides 300 b on both side surfaces of the longitudinal alignment plate 300. The paper discharge tray 301 includes a stacking plate 302 and an elastic body 303. The stacking plate 302 is provided horizontally via the elastic body 303. The stacking plate 302 moves in the vertical direction according to the number of sheets stacked on the stacking plate 302, i.e., the weight of the sheets (a double-headed arrow S in FIGS. 5B and 5C). The movement of the stacking plate 302 can also be performed by a driving motor. In this case, the control section 111 controls the driving motor according to the number of processed sheets, the weight of stacked sheets, or the like. The stacking plate 302 is substantially perpendicular to the bent section 300 a of the longitudinal alignment plate 300. In FIGS. 5A to 5C, a form in which the bent section 300 a and the guides 300 b are integrally molded is shown. However, the bent section 300 a and the guides 300 b may be separated. The longitudinal alignment plate 300 may be configured to be extensible in the sheet conveying direction like the longitudinal alignment plate 200 explained in the second embodiment.

FIGS. 6A to 6E are diagrams for explaining the operation of the discharged sheet aligning device shown in FIGS. 5A to 5C. First, the decolored sheet P1 is successively conveyed from the first conveying path 105 to the paper discharge tray 301 via the paper discharge member 117 a (FIG. 6A). The sheet P1 passed the paper discharge member 117 a is guided and laterally aligned by the guides 300 b provided on both the side surfaces of the longitudinal alignment plate 300. Specifically, the discharged sheet P1 is regulated by the aligning roller 121 a to come into contact with the bent section 300 a while being laterally aligned by the guides 300 b (FIG. 6B). The leading end of the sheet P1 is stacked in contact with the bent section 300 a and the paper discharge tray 301 lower in the vertical direction (FIG. 6C). The conveyed sheet P1 is aligned at the top of the stacked sheet P1 by the bent section 300 a (FIG. 6D). When the longitudinal alignment plate 300 is opened, the stacked sheets P1 are in an aligned state (FIG. 6E).

As explained above, in the third embodiment, in addition to the characteristics in the first or second embodiment, it is possible to perform lateral alignment of a discharged sheet as well.

The color erasing apparatus explained in the embodiments is not limited to an apparatus that erases a color of an image using heat. For example, the erasing apparatus may be either an apparatus that erases a color of an image on a sheet by irradiating light on the image or an apparatus that erases an image formed on a special sheet. Alternatively, the erasing apparatus may be an apparatus that removes an image on a sheet. The erasing apparatus only has to have a configuration for making an image invisible in order to make a sheet reusable.

Other Embodiments

The discharged sheet aligning device according to the embodiments explained above is not applied to the color erasing apparatus 1 alone. The discharged sheet aligning device can be applied to any apparatus as long as the apparatus includes a mechanism for paper discharge. For example, as shown in FIG. 7, a discharged sheet aligning device 400 according to the embodiments is attached to a paper discharge section of an image forming apparatus 2 such as an MFP (multi-functional peripheral) or a finisher that applies finishing (stapling, etc.) to sheets discharged from the image forming apparatus 2. This makes it possible to perform alignment of stacked sheets.

As explained above, with the discharged sheet aligning device according to the embodiments, it is possible to prevent a discharged and stacked sheet from being sticking out from a paper discharge tray because of a warp or the like and perform longitudinal alignment of the stacked sheet.

While certain embodiments have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the inventions. Indeed, the novel embodiments described herein may be embodied in a variety of other forms; furthermore, various omissions, substitutions and changes in the form of the embodiments described herein may be made without departing from the spirit of the inventions the accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the inventions. 

1. An erasing apparatus comprising: a paper feeding section configured to feed a sheet having a erasable image; a erasing section configured to erase the image; a paper discharge section including: a paper discharge member configured to discharge, downstream in a conveying path of the erasing section, the sheet from which the image is erased; and a paper discharge tray on which the discharged sheet is stacked; and a longitudinal alignment plate pivotably provided above the paper discharge tray and configured to align a leading end of the sheet stacked on the paper discharge tray.
 2. The apparatus according to claim 1, wherein the paper discharge section includes an aligning roller configured to bring the leading end of the sheet into contact with an inner wall of a distal end of the longitudinal alignment plate.
 3. The apparatus according to claim 1, wherein the inner wall of the distal end of the longitudinal alignment plate includes an elastic layer.
 4. The apparatus according to claim 1, wherein the paper discharge tray includes: a stacking plate on which the sheet is stacked; and an elastic body configured to urge the stacking plate upward.
 5. The apparatus according to claim 4, wherein the stacking plate is provided horizontally.
 6. The apparatus according to claim 5, wherein the longitudinal alignment plate includes guides on both side surfaces.
 7. The apparatus according to claim 6, wherein the guides are molded integrally with the longitudinal alignment plate.
 8. The apparatus according to claim 1, wherein the longitudinal alignment plate aligns the leading end of the sheet in cooperation with the paper discharge tray.
 9. The apparatus according to claim 8, wherein the paper discharge section includes an aligning roller configured to bring the leading end of the sheet into contact with at least one of an inner wall of a distal end of the paper discharge tray and an inner wall of a distal end of the longitudinal alignment plate.
 10. The apparatus according to claim 9, wherein the inner wall of the distal end of the paper discharge tray and the inner wall of the distal end of the longitudinal alignment plate include elastic layers.
 11. The apparatus according to claim 10, wherein the paper discharge tray includes: a stacking plate on which the sheet is stacked; and an elastic body configured to urge the stacking plate upward.
 12. The apparatus according to claim 11, wherein the elastic body is provided upstream in a conveying direction of the paper discharge tray, and the stacking plate inclines downstream in the conveying direction.
 13. The apparatus according to claim 12, wherein the distal end of the longitudinal alignment plate is bent substantially vertically and can come into contact with the distal end of the paper discharge tray.
 14. The apparatus according to claim 13, wherein the longitudinal alignment plate is extensible in a sheet conveying direction.
 15. The apparatus according to claim 14, wherein the longitudinal alignment plate includes: a first alignment plate including first engaging sections and a bent section bent substantially vertically; and a second alignment plate including, predetermined interval in the conveying direction, a plurality of second engaging sections configured to engage with the first engaging sections.
 16. The apparatus according to claim 15, wherein the bent section and the distal end of the paper discharge tray mesh with each other in a comb teeth shape.
 17. A discharged sheet aligning method comprising: feeding a sheet having a erasable image; erasing the image of the fed sheet with a erasing section; discharging and stacking, downstream in a conveying path of the erasing section, the sheet from which the image is erased onto a paper discharge tray; and a longitudinal alignment plate aligning a leading end of the sheet stacked on the paper discharge tray, the longitudinal alignment plate being pivotably provided above the paper discharge tray.
 18. The method according to claim 17, wherein the longitudinal alignment plate aligns the leading end of the sheet in cooperation with a distal end of the paper discharge tray.
 19. The method according to claim 18, wherein the longitudinal alignment plate is extensible in a sheet conveying direction.
 20. A discharged sheet aligning device comprising: a paper discharge section including: a paper discharge member configured to discharge a sheet; and a paper discharge tray on which the sheet discharged by the paper discharge member is stacked; and a longitudinal alignment plate pivotably provided above the paper discharge tray and configured to align a leading end of the sheet stacked on the paper discharge tray. 